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SARS Timeline
Nov 16 ‘02 Feb 11 ‘03 Feb 28 March 11 March 12 March 19 March 27 April 5 April 9 April 14 April 17 April 28
First cases Hong Kong WHO Sequence
retrospectively and Vietnam issues of suspected
Recognized, report out- travel agent, a
Guangdong, breaks in advisories coronavirus,
China hospital established
workers China
Acute coverup India
respiratory WHO admitted;
reported in issues SARS SARSGuangdong global made top
by China alert priority Vietnam
MOH contain-
Reported First ing virus
First in U.S. and SARS in (WHO)
SARS Europe Africa
case –
Vietnam
Hotel MHong Kong
Guangdong Province,
China A
A
H,JA
H,J
Hong Kong SAR
95 HCW
>100 close contacts
United States
1 HCW
I, L,M
I,L,M
K Ireland
0 HCWK
Singapore
34 HCW37 close contacts
C,D,E
C,D,E
B
B
Vietnam
37 HCW
21 close contacts
F,G
Canada
18 HCWF,G
11 close contacts
Effect of Travel and Missed Cases on the SARS EpidemicSpread from Hotel M, Hong Kong
SARS Hotspots (as of May 28, 2003)
# Probable Cases # Deaths
China 5322 321Hong Kong 1728 269Taiwan 596 76Singapore 206 31Canada 148 26United States 65 0Vietnam 63 5Philippines 12 2Other Countries 62 4
Total 8202 734
0
50
100
150
200
250
4,22
4,24
4,26
4,28
4,30
5,02
5,04
5,06
5,08
5,10
Number of SARS Cases Reported over Time (China)
Symptoms of SARS
• Cough• High fever• Severe pneumonia• Difficult to distinguish from other
respiratory diseases in early stages
1.6
7.2
29.2
18.7
21.5
18.016.1 16.5
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
0- 10- 20- 30- 40- 50- 60- 70-
( 1/1,000,000)
Incidence Difference across Different Age Groups (China)
CDC, 2003
0.0 0.0 0.93.0
5.0
10.0
17.6
28.026.3
0.0
5.0
10.0
15.0
20.0
25.0
30.0
0- 10- 20- 30- 40- 50- 60- 70- 80-
Fatality Rates of Different Age Groups
CDC, 2003
SARS DiagnosticsKey Messages
• SARS diagnostic assays are sensitive and specific, but may not provide definitive diagnosis early in the illness
• Changes in the quantity, type, and timing of specimens collected may improve detection of SARS-CoV infection
• Rapid and accurate diagnosis of other respiratory pathogens associated with SARS-like illness may help rule out SARS-CoV infection and calm public fears
• Interpretation of test results must take into consideration possibility of false positives and negatives; a clear strategy to minimize such possibilities and to confirm test results are essential
CDC, 2003
Definitions of Quarantine Isolation
• Separation and restricted movement of ill persons with contagious disease
• Often in a hospital setting• Primarily individual level, may be populations
Quarantine• Separation and restricted movement of well persons
presumed exposed to contagion• Often at home, may be designated residential facility• Applied at the individual or community level
May be voluntary or mandatory
CDC, 2003
A collective action for the common good predicated on aiding individuals infected or exposed to infectious agents while protecting others from the dangers of inadvertent exposure
Public good Civil liberties
Modern Quarantine
Meeting needs of individuals infected and exposed is paramount
CDC, 2003
Key Issues to Consider
• Surveillance• Clinical evaluation • Infection control measures• Patient isolation• Engineering controls• Exposure evaluation• Staffing needs and personnel policies• Access controls• Supplies and equipment• Communication
CDC, 2003
SARS Mysteries
Origin of SARS – animal reservoirs?
Is coronavirus the etiologic agent?
• Cases without antibody
• Non-cases with antibody
SARS Mysteries (continued)
What proportion of exposed persons
develop clinical disease and death?
• Proportion of exposed, infected and asymptomatic
Are there asymptomatic carriers?
• Reports of cases without known source of exposure
SARS Mysteries (continued)
What causes “super shedders”?• Host characteristics; e.g., age
• Agent characteristics – “virulent strain”
Is pathology caused by the virus or the
response to the virus?
• AIDS patients appear to be resistant to SARS
SARS Mysteries (continued)
Will SARS reappear in the fall?
• SARS is transmitted through the respiratory route. These diseases, like influenza, tend to have a season cycle with resurgence in the late fall, winter and early spring